Atal Bihari Vajpayee served as the prime minister of India for 13 days in 1996 and then for two incomplete terms from 1998 to 2004. He is the fifth longest-serving PM of India.
Narendra Modi is the current and the fourth longest-serving Prime Minister of India. His first term started in 2014 and was re-elected in 2019.
Manmohan Singh served as the prime minister of India from 2004 to 2014. He is the third longest-serving PM of India.
Indira Gandhi, the first woman prime minister of India, served the nation for two terms -- from 1966 to 1977 and 1980 to 1984. She is the second longest-serving PM of India.
Pandit Jawaharlal Nehru, India's first prime minister, served for 17 years from 1947 to 1964. He is the longest-serving PM of India.